While most patients treated with BTK inhibitors (BTKis) will achieve at least a partial response (PR) [1–4], an initial worsening of lymphocytosis concurrent with shrinking of nodal disease, captured as PR with lymphocytosis (PR-L), is common with BTKi and due to redistribution of CLL cells from lymph nodes to the blood [5]. This evidence concerns the gene BTK and B-cell chronic lymphocytic leukemia.